Archived:Loader ignores transparency information in PNG images in Java ME (Known Issue)
There is a bug in the Nokia M3G (JSR-184) implementation.
Nokia 6630 ignores all types of transparency; Nokia 6680 handles raw alpha channels correctly, but ignores color-key and palette transparency.
As a workaround use Image.createImage to load the PNG, and then construct an Image2D from that. As an alternative, embed the image into a host M3G file.